Yasuo Shioya

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Bovine immature oocytes do not have the ability to block polyspermic penetration. The present study was conducted to determine whether this is correlated to cortical granule (CG) distribution and the competence of oocytes to release CG upon sperm penetration, and whether the ability of bovine oocytes to release CG develops during in vitro maturation.(More)
We present imaging data and photometry for the COSMOS survey in 15 photometric bands between 0.3µm and 2.4µm. These include data taken on the Subaru 8.3m telescope, the KPNO and CTIO 4m telescopes, and the CFHT 3.6m telescope. Special techniques are used to ensure that the relative photometric calibration is better than 1% across the field of view. The(More)
Polyspermy is one of the unresolved problems that exist regarding pig oocytes matured and inseminated in vitro. Quantitative study of the changes in the cortical granule (CG) population in oocytes is essential for understanding the mechanism of how oocytes block polyspermic penetration and for developing the optimum conditions for in vitro maturation (IVM)(More)
Pig oocytes were examined to test their ability to undergo cortical granule exocytosis upon penetration by spermatozoa during meiotic maturation. Immature or maturing oocytes (cultured in vitro for 0 h, 26 h and 46 h) were inseminated with ejaculated boar spermatozoa in vitro. Before and after insemination, oocytes were stained with peanut agglutinin(More)
The present study was conducted to examine distributional changes of cortical granules (CGs) during meiotic maturation and fertilisation in vitro and the developmental ability in bovine oocytes classified by cumulus cells. The oocytes were classified by the morphology of their cumulus cell layers as follows: class A, compact and thick; class B, compact but(More)
We report the discovery of a large-scale structure of Lyman α emitters (LAEs) at z = 4.86 based on wide-field imaging with the prime-focus camera (Suprime-Cam) on the Subaru telescope. We observed a 25 ′ × 45 ′ area of the Subaru Deep Field in a narrow band (NB711, λ C = 7126Å and FWHM= 73Å) together with R and i ′. We isolate from these data 43 LAE(More)
  • C Scarlata, C M Carollo, S Lilly, M T Sargent, R Feldmann, P Kampczyk +11 others
  • 2007
Motivated by the desire to reliably and automatically classify structure of thousands of COSMOS galaxies, we present ZEST, the Zurich Estimator of Structural Types. To classify galaxy structure, ZEST uses (1) five nonparametric diag-nostics: asymmetry, concentration, Gini coefficient, second-order moment of the brightest 20% of galaxy pixels, and(More)
We present the results from a submillimetre (submm) survey of a sample of 23 giant Lyα emitting nebulae in the overdensity at z = 3.09 in the SA 22 field. These objects, which have become known as Lyα Blobs (LABs), have a diverse range of morphology and surface brightness, but the nature of their power-source remains unclear, with both cooling flows or(More)
  • T Nagao, K Motohara, R Maiolino, A Marconi, Y Taniguchi, K Aoki +2 others
  • 2005
We present a very deep near-infrared spectroscopic observation of a strong Lyα emitter at z = 6.33, SDF J132440.6+273607, which we used to search for Heiiλ1640. This emission line is expected if the target hosts a significant number of population III stars. Even after 42 ksec of integration with the Subaru/OHS spectrograph, no emission-line features are(More)
A recent all-object spectroscopic survey centred on the Fornax cluster of galaxies, has discovered a population of sub-luminous and extremely compact members, called " ultra-compact dwarf " (UCD) galaxies. In order to clarify the origin of these objects, we have used self-consistent numerical simulations to study the dynamical evolution a nucleated dwarf(More)